After perhaps half an hour, it was time. We made our way to the small book stall, which had been built into an alcove close to the main spectator entrance. There was quite a crowd here, for this was where you congregated for your “official” guided tours.

I had no problem recognizing Lucia.

She had exactly the look that had characterized the women and girls of the Order: not tall, stockily built, with the oval face and pale gray eyes of that huge subterranean family. I had had a lot of trouble figuring out ages in the Crypt, but Lucia looked genuinely young — perhaps sixteen, or even younger. She had blue-tinged sunglasses pushed up on her head. But her simple blue dress was grimy, the hem ripped; it looked as if she had been wearing it for days.

She was heavily pregnant, I saw, startled.

When she saw me standing before her — and she recognized my similar features — her eyes widened, and she clutched the hand of the boy with her.

He was quite different: perhaps a couple of years older, taller, slim, with reddish hair that was already receding from a pale, rounded brow. His eyes were clear blue, and he peered at us suspiciously.

“So here we are,” Peter said. “I take it you’re Lucia — you speak English?”

“Not well,” she said. Her voice was husky, her English heavily accented.

“But I do,” said the boy, Daniel. “I’m an American.”

“Good for you,” said Peter dryly.

I tried to reduce the tension. “My name is George Poole. Lucia, it seems we are distant cousins.” I smiled, and she nervously smiled back. “And this is Peter McLachlan. My friend.”

Daniel wasn’t reassured. He looked defiant, but scared. He was already out of his depth. His Internet contact with us, conducted from the safety of his home or some cybercafй, was one thing, but maybe he was having second thoughts when confronted by the reality of two hefty, sweating middle-age men. “How do we know we can trust you?”

Peter snorted, sweating. “You contacted us, remember?”

I held up a hand and gave Peter a look: Go easy on them. I said, “I’m family, and Peter is an old friend. He’s here to help. I’ve known him all my life, and I trust him. Let’s just talk. We can stay in public places all the time. Anytime you like you can just walk away. How’s that?”

Daniel, still uncertain, glanced at Lucia. She just nodded weakly.

So we walked around the curving walkway. Lucia, gravid, walked heavily and painfully, her hand on her back. Daniel supported her, holding her arm.

I whispered to Peter, “What do you think?”

He shrugged. “That poor kid looks as if she’s going to pup any minute … You think Daniel’s the father?”

“I have no idea,” I said truthfully. But somehow I thought it wouldn’t be as simple as that.

Peter chewed a nail, a habit I hadn’t noticed before. “I wasn’t expecting this. This is supposed to be about your sister, and her cult. What are we getting into here?” He had seemed oddly jumpy all day, and his nervousness was getting worse. I had no idea why — but then I knew there was a lot about Peter, not least why he was in Rome in the first place, he wasn’t telling me.

The Colosseum is a big place, and we soon found an out-of-the-way alcove where it looked as if we would be undisturbed. Lucia found a place to sit, on a worn row of steps in the shade. Daniel stood over her protectively. Peter had a couple of bottles of water in his day bag. He gave one to Lucia, and she sipped it gratefully. She was breathing hard, I saw, and sweating heavily.

“So,” said Peter. “Tell me how you got in touch with us.”

Daniel shrugged. “It wasn’t hard … I thought I needed to find somebody outside the Order, and yet with a connection. You see what I mean?”

“Yes,” I said. “Somebody else asking awkward questions.”

And so, he said, he had hacked into the Order’s email streams looking for likely candidates. “It was difficult — the Order’s traffic is heavily encrypted — but—”

“But you’re a smart little hacker,” said Peter unsympathetically.

Daniel’s eyes flashed. “I did what I had to do.”

Peter said, “Let’s cut to the chase. She’s your girlfriend, and you got her pregnant. Is that the story?”

“No!” Daniel’s denial was surprisingly hot. “I wouldn’t be so stupid.”

I studied Daniel. “How old are you, son?”

He was just seventeen; he looked older. No wonder he was out of his depth.

“If you aren’t the father, how did you get involved with Lucia?”

For the next couple of minutes he gabbled out something of his life story — how he was the son of a diplomat, a student at an expat school in the city — and how his harmless flirtation with a pretty girl he spotted at the Pantheon had led him into deep waters. When he had gotten all this out, he seemed drained, some of his nerve gone. “I was only fooling. I didn’t expect it to turn out like this. But when she asked me for help, I couldn’t refuse, could I?”

“No,” I said. “I’m sure you did the right thing.”

Since she’d come to him he had been hiding her away, though he wouldn’t say where. From her look, I doubted it was in much comfort. He hadn’t told his parents what he was doing. He had done his best, I thought, and I wondered how well I would have coped with such a situation when I was seventeen.

I asked Lucia her age. I was shocked to find she was only fifteen. She looked too worn out for that.

“All right,” said Peter. “Let’s start at the beginning. Lucia — you’re trying to get away from something. From the Order?”

That took a little translating. “Yes,” she said, “from the Order.”

“And that’s why you contacted Daniel here.”

“There was nobody else,” she said miserably. “I didn’t want to get him into trouble, but I didn’t know what else to do, and—”

“It’s okay,” I said. “Just tell us. Why do you want to leave the Order?”

“Because they took my baby away,” she said.

I did a double take. “Your first baby. You’re now pregnant with your second.”

“Yes.” Lucia’s eyes were downcast, and she rested her hands on her belly.

“Who was the father?”

“His name was Giuliano … something. His name doesn’t matter. He was brought in.”

“Who by?”

“By the cupola.” I didn’t understand that, and she said, “By Rosa Poole. Your sister.”

Peter and I exchanged glances.

Hesitantly I touched her hand. “You can tell us. Were you raped?”

“No.” She closed her eyes, shaking her head, almost irritably. “You don’t understand. Daniel asked the same questions. People never listen.”

I backed off. “I’m sorry. Just tell us.”

“Giuliano was brought in, and he made me pregnant, and I had my baby, and they took her away. And now this.” She patted her bulge. “I don’t want to lose this one, too. And I don’t want baby after baby. I don’t want this.” Suddenly she was crying, a flood of tears.

We three males all scrambled in our pockets; the comedy routine concluded when Daniel was the first to produce a tissue.

Peter sat back and blew out his cheeks. “Deeper and deeper. So who was the father of this second kid?”

“The same guy,” said Daniel. “The same asshole. This Giuliano, whatever.”

Peter frowned. “Then how come she doesn’t know his name?”

Daniel took a breath. “Because he only slept with her once.”

Peter thought that over, and laughed out loud.

Daniel, hotly embarrassed, said, “You don’t know the half of it, man.”

Lucia said desolately, “I told you they wouldn’t believe me.” With a tissue clutched to her nose, she looked up at me through water-filled eyes heartbreakingly like my own.

“Let’s all take it easy,” I said. “Lucia, you say you don’t want to have baby after baby … Is that what they asked you to do? The Order — umm, my sister?”